Carpet cutter

ABSTRACT

A carpet cutter has a body having a handle or grip in the upper part thereof, and a blade which is retentively secured in such a manner that its position is variable, if necessary, within a range of positions from the front face of the handle or grip to the front face of the body. The blade is provided with an edge on a lateral side thereof. The underside of the body is a plane making an acute angle in relation to the edge of the blade. The front end of the blade is adapted to be upwardly protrudable beyond the front edge of the underside of the body.

United States Patent 1191 [111 3,726,010 Yokoyama 5] Apr. 10, 1973 [54] CARPET CUTTER 3,530,579 9 1970 Dahlke ..30/293 X ....30/294 X [76] Inventor: Kiyofum Yokoyama, No. 83, 3621'573 111/1971 Summers Nakazakbcho, Kitafku, Osaka, 3,581,397 6/1971 Kochanowskn ..30/293 22 Filed: Apr. 13, 1971 211 App]. No.: 133,676

52 vs. C]. ..30/293, 30/320, 30/335 51 1m. (:1 ..B26b 1/08, B26b 3/08 [58] Field of Search ..30/335, 320, 162,

[56] References Cited UNITED STATES PATENTS 1,327,155 1/1920 Gottschalk ..30/171 3,314,148 4/1967 Foellmi ..30/162 3,316,635 5/1967 MCITOW et 3.1. ..30/335 X 3,395,453 8/1968 Prater..... ..30/294 X 3,448,518 6/1969 Sklar ..30/162 Japan Primary Examiner-Robert C. Riordon Attorney-Wenderoth, Lind & Ponack ABSTRACT A carpet cutter has a body having a handle or grip in the upper part thereof, and a blade which is retentively secured in such a manner that its position is variable, if necessary, within a range of positions from the front face of the handle or grip to the front face of the 5 Claims, 7 Drawing Figures PA Emtn R 1 @1913 3,726,010

SHEET 1 OF 3 4] KIYOFUMI YOKOYAMA INVENTOR.

Mania/4nd Attorneys PAIENI APR 1 01m SHEET 2 [IF FIG? Attorneys mm W.

w MQ m (KB P'AIEMWM 0W5 3.72am 1 0 SHEET 3 OF 3 KIYOFUMI YOKOYAMA,

INVENTOR.

Attorneys CARPET CUTTER This invention relates to a carpet cutter for use in cutting the edge of a carpet.

When laying a carpet properly on the floor, it is necessary that the carpet be so cut that the edges thereof are accurately aligned with the walls, but the task of cutting a carpet properly involvesgreat difficulty, necessitating considerable skill.

A first object of this invention is to provide a carpet cutter which enables a skilled worker to cut acarpet in a much shorter time than in the case of the conventional operation, also enabling an unskilled person to cut a carpet accurately without difficulty.

A second object of this invention is to provide a carpet cutter having a simple construction, the edge of the blade thereof being retainable by a simple adjustment in a position which is accurate and convenient for cutting.

A third object of this invention is to provide a carpet cutter enabling the blade to be broken off when it becomes dull, so that the edge thereof will always be in a fresh and sharp condition.

A fourth object of this invention is to provide a carpet cutter which can be carried in a pocket safely by withdrawing the edge of the blade.

A fifth object of this invention is to provide a carpet cutter capable of cutting a carpet easily without the risk of damaging the edge of the blade or scratching the wall surface owing to a direct contact with the wall surface.

These and other objects are accomplished by the parts, improvements, combinations and arrangements comprising the invention, a preferred embodiment of which is shown by way of example in the accompanying body 10, a blade guide frame secured to said blade casing 14, and a blade 16 mounted on said guide frame. The cross section of the handle or grip is in the shape of a segment of a circle broken on the side of the chanslot 17.

Furthermore, as shown in F163, a bolt bore 18 and a threaded hole 19 are formed with the slot 17 therebetween adjacent the upper end of the handle 11, the channel 13 being reducible by drawing both sides of the handle 11 together by threading a threaded bolt 20 which is loosely fitted inside the bore 18 into the threaded hole 19, the blade casing 14 which is fitted inside the channel 13 being retentively secured between opposite sides of the channel 13.

Therefore, the blade casing 14 can be removed from the channel 13 by loosening said bolt 20.

The foregoing guide frame 15 is formed by bending a metal plate, both sides and the back thereof being indrawings, and hereindescribed in detail. Various modifications and changes in details of construction are comprehended within the scope of the appended claims This invention consists of a body consisting of a base and a handle for gripping by hand, said body retaining a blade at a proper .angle, a blade casing secured to. said body, and a blade so mounted as to be slidable relative to said blade casing, said blade being retainable at any position relative to the blade casing.

F161 is a perspective view of the carpet cutter according to this invention.

F162 is a longitudinal section of the carpet cutter according to this invention.

FIG.3 is a cross section of the handle or grip of the carpet cutter according to this invention.

FIG.4 is a cross section on an enlarged scale of a blade'casing.

FlG.5 is a disassembled perspective view taken from the rear side of a slide box.

F166 is a side elevation showing the use of the carpet cutter according to this invention.

FlG.7 is a cross sectional side elevation showing an edge of a carpet cut by the carpet cutter according to this invention.

This carpet cutter comprisesin combination a body 10 consisting of a base 12 in the form of a substantially truncated pyramid and a handle 11 which is formed integrally with said base l2, said body 10 consisting of a solid material, such as a light alloy. and the like, a blade casing 14 consisting of a hard synthetic resin or the like fitted in a channel 13 formed'on the front face of the tegrally secured in close contact with the blade casing 14.

As shown in F164, the guide frame 15 has guide grooves 21 and 22 formed on the opposite inner sides thereof, the opposite edges of the blade 16 being slidably fitted into. said grooves 21 and 22.

The numeral 23 designates a slide box, both edges thereof also being slidably fitted into said grooves 21 and 22. FIG.5, shown in FIG. 5 said slide box 23 is fabricated by press molding a metal plate or the like, a

spring plate 24 being secured thereinside. The spring 1 plate 24 is bent at one end thereof, spring elements 25 and 26 being integrally formed on both sides thereof, triangular projections 27 and 28 which are formed by bending the spring elements 25 and 26 respectively being caused to protrude outwardly through notches 29 and 30 provided on both sides of the slide box 23.

A pin 31 is secured to the spring plate 24, said pin 31 being fitted into a bore 32 formed at the upper end of the blade 16.

in F the slide box 23, springplate 24and the blade 16 are all shown with the reverse sides thereof turned upward, and therefore when they are fitted into the channel 13 the blade 16 is placed inside, the slide box 23 being placed thereon, the inwardly facing pin 31 being fitted into the bore 32 at the upper end of the blade 16, and said blade 16 sliding along the grooves 21 and 22 together withthe slide box 23as shown in FIG.4.

Moreover, as shown in FIG.1, a number of engaging notches 33 are provided in alignment at a predetermined pitch along the inwardly facing edge on the left side of the guide frame 15, the projection 28 which protrudes from the slide box 23 engaging with one of the said notches 33 to serve as a detent.

The blade 16 has a cutting edge 34 formed along the right side thereof as shown in F101. The blade 16 is fabricated with tempered steel or the like and provided with a number of slender grooves 35 therein for convenience in breaking off worn or dull portions, said grooves 35 being at the same pitch as the engaging notches 33 and slanting downwardly toward the right side of the blade, that is, slanting downwardly so that the edge 34 of the blade will come underneath.

The underside 36 of the base 12 is a flat plane so inclined as to make an acute angle with the blade 16 as shown in FIG.2.

Said underside 36 is square in shape, the front edge 37 thereof being rectilineal, the front face 38 of the body 12 which rises upwardly from said front edge 37 being gradually inclined backwardly with a smooth curvature to meet a plane extending to the upper end of the handle 11.

Moreover, both side faces as well as the rear face of the base 12 constitute a smoothly curved surface, which is conjoined with the curved surface of the handle 11.

On the underside 36 of the body 12 is formed a recessed bore 39 extending toward the base of the channel 13 as shown in FIG. 2, and a threaded hole 40 extends from the channel 13 through the bottom of said recessed bore 39 and concentric therewith, and an adjusting bolt 41 is threaded into said hole 40, the rear face of the lower end of the blade guide frame 15 being engaged by the front end of the bolt 41.

Now, the embodiment described hereinbefore is used in the manner set forth hereunder. A carpet 43 is preliminarily out about cm longer than the floor surface 43, duplex adhesive tape 44 being pasted on the floor surface 43, and the carpet 42 being placed thereon with the end portion 45 of the carpet 42 bent upwardly and rectangularly along the wall surface 46.

Then, the underside 36 of the base 12 is placed on the upper surface of the carpet 42 by gripping the handle 11 of the carpet cutter of this invention as shown in F106, the front end of the blade 16 being caused to cut into the carpet 42 by bringing the front edge 37 into contact with the interior angle of the rectangularly bent carpet, the body being moved in the direction of the edge 34. Thus, the blade 16 moves along the wall surface 46 while obliquely cutting the bent portion of the carpet 42 with the edge 34 as shown in F166 Consequently, when the upwardly bent portion 45 has been removed, the cut end 47 of the carpet 42 is restored to its original position by the intrinsic resilience of the carpet 42, with the result that the cut end 47 turns obliquely downwardly, the triangular front end portion 48 formed at the upper edge of said cut end 47 being brought in close contact with the wall surface 46.

More particularly, the carpet 42 is brought into contact with the wall surface 46, the triangular end portion 48 functioning as a spring. Since the carpet 42 and the wall surface 46 are in perfect contactwith each'other, no gap remains between the carpet 42 and the wall sur' face 46, there being no risk of wrinkles occuring along the peripheral rim of the carpet 42 due to an excess in the length of the edgeof-the carpet 42.

This carpet cutter makes it possible to cut a carpet without difficulty simply by pressing the bent portion 45 of the carpet 42 against the surface of a wall 46 or a pillar with the front edge 37 of the body 12 and moving the cutter along said bent portion 45, with the result that a speed-up of the cutting operation can easily be achieved.

Moreover, since the blade 16 is guided by the wall surface which acts as a straight edge, the carpet is accurately out even when the wall surface is not rectilineal or in a room where the wall surfaces are narrow and intricate. Since there is no risk of a cutting error or a gap occuring, the necessity of patching after the cutting operation can be avoided, as a result of which this carpet cutter not only helps to greatly increase the operational efficiency, but enables any unskilled person to conduct the cutting operation without difficulty.

In order to cut the carpet 42 as described hereinbefore, it is necessary that the blade 16 should be positioned to cut into a portion higher than the interior angle of the upturned carpet 42 by extending said blade farther than the front edge 37 of the base 12 as shown in FIG.6, and this control of the forward extension of the blade 15 is accomplished by rotating the adjusting bolt 41, thereby controlling the position of the guide frame 15 by the front end of said adjusting bolt 41.

The downward extension of the blade 16 must be adjusted taking into consideration the fact that the carpet 42 can be accurately cut and that the front end of the blade 34 should not be damaged by nor should it damage the wall'surface due to contact therewith, and this adjustment is effected by sliding the slide box 23 along the guide frame 15.

In accordance with the movement of the slide box 23, the triangular projection 28 protruding from the side of said slide box 23 engages with or disengages from the notches 33 provided in alignment along the inwardly facing edge 49 of the guide frame 15, thereby varying the downward extension of the blade 16 which moves therewith.

The slide box 23 is not easily movable when the projection 28 is in engagement with any of the engaging notches 33, and therefore the blade 16 is immovable during the carpet cutting operation.

The triangular projection 27 protruding from the other side of the slide box 23 brakes the slide box 23 by pressing against the other inwardly facing edge of the guide frame 15.

Since both the handle 11 and the body 10 are small in size and fabricated of a light alloy, such as an aluminum alloy and the like, or a light and hard synthetic resin, the carpet cutter of this invention is light, smallsized, and handy to carry in a pocket. This cutter is quite safe, the edge of the blade 16 being retractable from the underside of the body 10 when carried in a pocket. I

If the blade 16 loses its sharpness, the front end thereof can be broken off along the groove 35, thereby providing a fresh edge 34 for use.

I claim:

1. A carpet cutter comprising a body consisting of a base having a substantially square plane surface on the underside thereof and a handle formed integrally with said base on the upper portion thereof, the front face of said body having a channel therein, a blade guide frame secured to said channel, said blade guide frame having a groove on both sides thereof, a blade slidably mounted in said grooves at an acute angle to the plane surface on the underside of said base, a slide box slidably mounted in said grooves and connected with the upper portion of said blade, and a detent projection on said slide box, the inwardly facing edge of one of said grooves having a plurality of notches at a predetermined pitch therealong, said detent projection being engageable securely and disengageably in said notches during movement of said slide box along said guide frame, whereby said blade can be extended beyond or retracted from the front edge of said base.

2. A carpet cutter as claimed in claim 1, wherein said handle has a slot therethrough in the center of said channel and a threaded hole in the upper portion of said handle on one side of said slot opening into said slot and a bolt hole in'the portion of the handle on the other side of the slot and aligned with said threaded hole, a bolt threaded into said threaded hole through said bolt hole, and a blade casing having said blade guide frame secured therein and fitted into said channel, whereby said blade casing can be releasably clamped in said channel by rotating said bolt.

3. A carpet cutter as claimed in claim 2, wherein said base has a threaded hole extending therethrough from the underside of said base to the bottom of said channel and a bolt is threaded into said threaded hole and contacts the lower terminal portion of said blade casing, whereby the blade is adjustable in the forward direction of the front edge of said base by rotating said bolt.

4. A carpet cutter as claimed in claim 1, wherein said blade has a plurality of grooves thereacross at a predetermined pitch to make possible breaking off portions of the blade the edge of which has become dull.

5. A carpet cutter as claimed in claim 1, wherein a further resilient projection is provided on the opposite side of said slide box from said detent projection and pressing against the other inwardly facing edge of said groove. 

1. A carpet cutter comprising a body consisting of a base having a substantially square plane surface on the underside thereof and a handle formed integrally with said base on the upper portion thereof, the front face of said body having a channel therein, a blade guide frame secured to said channel, said blade guide frame having a groove on both sides thereof, a blade slidably mounted in said grooves at an acute angle to the plane surface on the underside of said base, a slide box slidably mounted in said grooves and connected with the upper portion of said blade, and a detent projection on said slide box, the inwardly facing edge of one of said grooves having a plurality of notches at a predetermined pitch therealong, said detent projection being engageable securely and disengageably in said notches during movement of said slide box along said guide frame, whereby said blade can be extended beyond or retracted from the front edge of said base.
 2. A carpet cutter as claimed in claim 1, wherein said handle has a slot therethrough in the center of said channel and a threaded hole in the upper portion of said handle on one side of said slot opening into said slot and a bolt hole in the portion of the handle on the other side of the slot and aligned with said threaded hole, a bolt threaded into said threaded hole through said bolt hole, and a blade casing having said blade guide frame secured therein and fitted into said channel, whereby said blade casing can be releasably clamped in said channel by rotating said bolt.
 3. A carpet cutter as claimed in claim 2, wherein said base has a threaded hole extending therethrough from the underside of said base to the bottom of said channel and a bolt is threaded into said threaded hole and contacts the lower terminal portion of said blade casing, whereby the blade is adjustable in the forward direction of the front edge of said base by rotating said bolt.
 4. A carpet cutter as claimed in claim 1, wherein said blade has a plurality of grooves thereacross at a predetermined pitch to make possible breaking off portions of the blade the edge of which has become dull.
 5. A carpet cutter as claimed in claim 1, wherein a further resilient projection is provided on the opposite side of said slide box from said detent projection and pressing against the other inwardly facing edge of said groove. 